Mounting of gun muzzle devices



2 Sheets-Sheet 1 F. A. PACHMAYR ETAL MOUNTING OF GUN MUZZLE DEVICESINVENTORS FRANK A. PACA/MA v2 WALTEQ R NASS June 21, 1966 Filed July 101962 UbQ hw A TTO RNEY June 21, 1966 F. A. PACHMAYR ETAL 3,257,108

MOUNTING 0F GUN MUZZLE DEVICES Filed July 10, 1962 2 Sheets-Sheet 2 INVEN TORS FRANK A. PACHMAVE IgALTEQ R- MASS ATTORNEV 3,257,108 MOUNTINGOF GUN MUZZLE DEVICES Frank A. Pachmayr, Culver City, and Walter R.Nass, Escondido, Calif., assignors to Firearm Accessories, Inc., LosAngeles, Calif., a corporation of California Filed July 10, 1962, Ser.No. 208,732 19 Claims. (Cl. 269--45) This invention relates to improvedapparatus for mounting a muzzle device, such as a shot gun choke, on theforward end of a gun barrel.

The attachment of a choke device or the like to a gun barrel alters theaiming characteristics of the gun in a manner requiring compensation forthis change. For one thing, the muzzle attachment normally reduces therecoil of the gun, and because of this reduction in recoil tends tocause the gun to hit a target slightly lower than if no muzzle devicewere present. Further, since the muzzle device is of a diameter somewhatlarger than the rest of the barrel, the application of the attachment tothe barrel usually requires elevation of the forward sight of the gun,and for this reason also the gun may hit a target slightly low withrespect to the sighting line.

To compensate for the 'above discussed tendency of a gun having a muzzleattachment to shoot low, it has been found desirable to mount suchmuzzle attachments in positions of slight angularity with respect to themain axis of the gun barrel. More particularly, the muzzle attachment isso mounted as to be aimed slightly upwardly, preferably at an anglebetween about degrees and 1 /2 degrees. The general object of thepresent invention is to provide apparatus for thus mounting a UnitedStates Patent 0 3,257,108 Patented June 21, 1966 form of alongitudinally slit radially expansible sleeve, adapted to be expandedby a suitable cam type axially movable mandrel. In another form of theinvention, the expansible unit may bean elastomeric ring adapted toexpand radially upon the application of axial compressive forcesthereto. It is also contemplated that the locating structure forengaging the rear end of the barrel may have portions of severaldifferent diameters, for engaging and locating any of several differentsizes of gun barrels.

The above and other features and objects of the present invention willbe better understood from the following detailed description of thetypical embodiment illus- FIG. 3 is an enlarged fragmentaryrepresentation of the apparatus of FIG. 1;

muzzle attachment at a predetermined very accurately I measurable slightupward angle with respect to a gun barrel, to effect the desiredcompensation for the change in aiming characteristics of the gunresulting from the application of the muzzle attachment to the barrel.In a device embodying the invention, the muzzle attachment and gunbarrel are firmly held in the desired positions of relative angularity,while a rigid connection is made between the two units. This connectionmay be effected in any desired manner, but for maximum simplicity ispreferably attained by merely applying a strong bonding cc ment, such asan epoxy cement, to the attachment and gun barrel, and allowing thiscement to dry to a hardened condition while the attachment is held inthe proper position of angularity with respect to the gun barrel.

Certain specific features of novelty have to do with the preferredmounting of the unit which holds the muzzle attachment in a manner suchthat this unit is shiftable between two or more positions of differentangularity, in order that the attachment may be connected to a gunbarrel in any of various dilferent settings. Preferably, the unit forholding themuzzle attachment is mounted for pivotal movement betweenthese diiferent settings, and may be rigidly locked in any desiredsetting. For locking the unit in its ditferent positions, I may utilizeone or more screws, pins or other locking elements adapted to fit intomating apertures within the attachment holding unit and a coactingmounting structure, and serving to secure the unit in different settingswhen the locking element. is received within the different sets ofapertures. The rear end of the gun barrel may be accurately located byengagement with a positioning structure, which may consist of a partprojecting into and closely interfitting with the rear end of thebarrel. For effecting tight engagement of this locating structure withthe gun barrel, I may form the structure to be expansible radiallyoutwardly into tight gripping engagement with the inner surface of thebarrel. In certain forms of the invention, the eX-pansible unit takesthe FIG. 4 is a fragmentary view taken on line 44 of FIG. 3;

FIG. 5 is a fragmentary vertical section taken on line 55 of FIG. 3;

FIG. 6 is a vertical section taken on line 66 of FIG. 3;

FIG. 7 is a greatly enlarged fragmentary section taken on the generallyvertical arcuate line designated 77 in FIG. 3;

FIGS. 8, 9, 10 and 11 represent four variational types of devices forholding the rear or chamber end of the gun barrel in the presentapparatus;

FIG. 12 is a'view similar to a portion of FIG. 6, showing a differentform of muzzle device holder; and

FIG. 13 is a section taken on line 1313 of FIG. 12;

Referring first to FIG. 1, I have represented at 10 a conventional gunbarrel, to which there is to be applied a muzzle attachment 11. Theattachment and barrel are secured in desired positions of slightangularity with respect to one another by means of a device 12constructed in accordance with the invention, and typically mounted on atable or other support surface represented at 13. The apparatus 12includes a base rail or mounting part 14, a unit 15 for receiving andholding the muzzle attachment 11, and a second unit 16 for engaging andlocating the rear end of the gun barrel 10.

While it is to be understood that any of numerous different types ofmuzzle attachments may be connected to a gun barrel by the apparatus ofthe invention, there is typically illustrated in FIG. 2 one form ofmuzzle device which may be used, this device being shown for the purposeof representing broadly the manner in which the muzzle device maybereceived about the front of the gun barrel. In the FIG. 2 arrangement,the muzzle device 11 consists of a main tubular body 17, to the rearportion of which there is threadedly connected a securing ring 18, forretaining the choke device in a fixed axial position relative to a ring19 received within an annular groove 20 formed in the end portion of gunbarrel 10. Ring 19 may be formed of two semicircular sections, and mayhave the externally rounded cross-section illustrated in FIG. 2, forengagement at opposite axial sides by correspondingly curved annularsurfaces 21 and 22 of parts 17 and 18.

At locations forwardly of and rearwardly of ring 19, the externalsurface of barrel 10 has a slight clearance (at 23 and 24) from theinner surfaces of parts 17 :and 18, to allow for slight universaladjusting movement of muzzle device 11 relative to barrel 10 about acenter 25 lying on the axis 26 of barrel 10. To facilitate such limitedadjusting movement of the muzzle device, the curved surfaces 21 and 22of parts 17 and 18, and the engaged external surface of ring 19, may allbe of spherical curvature, about the discussed center 25. The clearancespaces 23 and 24 are of suflicient size to allow adjustment of themuzzle device to a position in which the axis 26' of the muzzle de viceis disposed at the proper angle with respect to barrel axis 26 to effectthe compensation which is required as a result of the presence of themuzzle device on the barrel. The usual forward sight 27 is of coursemounted on the muzzle device, for coaction with the rear sight 28 on therear portion of the barrel, in aiming the gun. At its forward end, thepart 17 of the muzzle device may carry a choke tube typicallyrepresented at 29, for controlling the pattern of the shot fired by thegun, with tube 29 being suitably secured to part 17, as by a threadedconnection at 30.

The rail or mounting member 14 may take the form of a horizontallyelongated rigid metal I beam, having the cross-section represented inFIG. 6. More particularly, this member 14 may have a vertical webportion 31, formed integrally with a bottom horizontal planar crosspiece or flange 32, and a top horizontal planar cross piece or flange33. Bottom flange 32 may be rigidly secured to the supporting table orstructure 13, as by bolts represented at 34 in FIG. 6, while the unitsand 16 are mounted to upper flange or plate 33.

Referring now to FIGS. 3, 4 and 6, the unit 15 for holding muzzleattachment 11 may include a first bracket section 35, having ahorizontal bottom flange 36 which is secured by bolts 37 to the upperside of top plate 33 of part 14. At one of the edges of bottom flange36, part 35 has an integral upstanding flange 33, whose inner and outerparallel surfaces 39 and 4t lie in vertical planes which extend parallelto, but are offset laterally from, the vertical plane of central web 31of rail 14. Adjacent the inner surface 39 of flange 38, there is mounteda block or section 41 containing a cylindrical passage 42 of a normaldiameter which is only slightly larger than the diameter of the outercylindrical surface of the muzzle attachment, to receive and effectivelylocate the attachment within block 41. An axially extending groove 127is provided in the undersurface of the top portion of block 41, of awidth to exactly receive and closely confine forward sight 27 or" themuzzle device, and thereby locate the sight in a precisely upwardlypointing position. At the side of block 41 which faces away from flange38, the material of this block may be interrupted by a horizontal slitor gap 43, with the vertical height of this gap being variable by meansof a screw 44, to tighten the wall of passage 42 against and about themuzzle device. Screw 44 has an upper head bearing downwardly against thetop surface of block 41, and extends downwardly through an un-' threadedbore 45 in the upper part of block 41, with the screw 44 within bore 46causes the upper head of thescrew to pull downwardly on the upperportion of block 41, and reduce the height of gap 43, therebyrestricting passage 42 to a diameter corresponding to the outsidediameter of the muzzle attachment. Block 41 may be formed of a material,such as metal, which is essentially rigid, but has a capacity for someresilient deformability, between a normal condition in which passage 42has a diameter slightly greater than the outside diameter of the muzzleattachment, to easily receive that attachment, and a reduced diametercondition in which the passage 42 is at least as small as the outsidediameter of the muzzle attachment, and tightly grips that attachment.The axis of passage 42 is designated 47, and of course coincides withaxis 26' of the muzzle attachment when the attachment is received withinpassage 42. Block 41 has, adjacent surface 39, a Vertical flange portion48, and has a vertical planar side surface 49 abutting against andslidably engaging surface 39 of flange 38. Surface 49 is retained inabutting engagement with surface 39 by means of a pivot screw 50, whoseend portion 51 is threadedly connected into block 41 (FIG. 4), and whoseenlarged head 52 abuts against the outer side flange 38. Cylindricalportion 53 of screw 50 is journalled within a correspondinglydimensioned cylindrical bore 54 formed in flange 38, to mount block 41and its integral flange portion 48 for pivotal movement relative toflange 38 about a horizontal axis 55 extending perpendicular to verticalsurfaces 39 and 49, and extending perpendicular to and intersecting axis47 of passage 42. The threaded portion 51 of screw 50 is a suflicientlytight fit within the coacting threaded opening in part 41 to retain thescrew in fixed relation relative to part 41, and the engagement of head50 with the outer side of flange 38 is sufliciently loose to allow thediscussed pivotal movement of part 41, while still retaining surfaces 39and 40 at all times in abutting engagement. Also, a second screw 153 maybe threaded into wall 48 and extended through and be movable within anarcuate slot 154 in flange 38, and have a head slidably engaging thisflange to assist screw 53 in holding flanges 33 and 48 together.

Flange portion 48 of part 41 contains a number of threaded openings 56through 62 (typically. six such openings), whose axes may extendparallel to axis 55, and which may typically the arranged along twoarcuate lines 164 and centered about axis 55. For coaction with theseopenings 56 through 62, the flange portion 38 of part 35 has cylindricalbores 63 which may also be located along the same two arcuate lines 164and 165 with respect to axis 55, and which are spaced approximately incorrespondence with the different apertures 56 through 62. The axes 64of openings 63, like the axes of the threaded openings 56 through 62,are parallel to pivotal axis 55. For locking the block 41 in any desiredpivotal position, there is provided a lock element 65 (FIG. 7), having athreaded portion 66 engageable within any of the different threadedopenings 56 through 62, and having a reduced diameter cylindricalportion 67 of a size corresponding to bores 63, and receivable therein.Thus, when the pin or element 65 is received within any one of thethreaded openings 56 through 62, and projects into the correspondingbore 63, the pin 65 acts to securely lock block 41 in a correspondingpredetermined position of angularity with respect to the later to bediscussed horizontal axis 68 of barrel holding unit 16. This axis 68with which axis 26 (FIG. 2) of the gun barrel'coincides when the latteris held in the apparatus, intersects the previously mentioned axis 47 ofpassage 42 (axis 26' of the muzzle device) at the location of transversepivotal axis 55 (and axis 25 of FIG. 2).

The various bores 63 are spaced apart slightly differently than are thevarious threaded openings '56 through 62, in a relation such that, inany one setting of block 42, pin 65 is receivable in locking relationwithin only one of the threaded openings and the associated opening 63.When the pin is received within the first threaded opening 56, and theassociated aperture 63, this may typically serve to lock block 41 in aposition in which its axis 47 coincides exactly with barrel axis 68, sothat the muzzle device is exactly aligned with the barrel. When thelocking pin is received within opening 57, muzzle device axis 47 may bedisposed at an upward angle of one-fourth of a degree relative to axis68 of the barrel. Similarly, upward inclinations of one-half degree,three-quarters degree, one degree, one and onefourth degree and one andone-half degree may be attained by connection of locking pin 65 intothreaded openings 58, 59, 66, 61 and 62 respectively. For indicating thesetting of block 41, the flange portion 48 of block 41 may have anarcuate edge 168 having markings 69 coacting with marking 78 on anarcuate' edge of a portion 171 of flange 38. In any of the varioussettings of block 41, only one of the markings 69 will exactly coincidewith one of the markings 70, with the angularity being indicated indegrees adjacent that pair or" coinciding markings.

The unit 16 for engaging and locating the rear or chambetween itsdifferent settings.

ber end of barrel may include a rigid typically level body member 71,which may have the essentially triangular cross-section represented inFIG. 5. The undersurface 72 (FIG. '5) of body part 71 may be planar, andslidably engage the upper surface of top flange 33 of part 14. Atopposite sides of flange 33, body part 71 may have two spaced paralleldepending flanges 73 and 74, to confine flange 33 between these flanges73 and 74 in a manner allowing shifting movement of part 71 along theupper surface of flange 33 only in a direction parallel to barrel axis68. The flange 74 may carry a pin 75 engageable with the undersurface offlange 33 to hold one side of body 71 against upward movement fromflange 33. At the opposite side of flange 33, depending flange 73, maycarry a locking screw 76, which is threadedly connected at 77 intoflange 73, and which has a tapered end portion 78 adapted to betightened inwardly against the underside of flange 33 in a mannerfrictionally locking block 71 in any desired setting relative to member14. Screw 76 may have a knurled knob 79 for facilitating the tighteningand loosening of the set screw.

At its side which faces toward the muzzle .attachment holding unit 15,block 71 has a vertical planar surface 80, disposed transversely of axis68. there is mounted a barrel locating part 81, having a flat surface 82engaging surface 80, and having a locating pin 83 received within acoacting recess in block 71 to locate part 81 relative to block 71. Theelement 81 forms a tubular sleeve 84 projecting toward unit 15, andcentered about axis 68. Sleeve 84 has a series of circularly spacedparallel longitudinally or axially extending slits 85, and is formed ofa resilient material (such as spring steel) allowing outward expansionof the sleeve to an increased diameter for gripping the inner surface ofbarrel 10. The free end of sleeve 84 is expansible outwardly in thismanner by means of an expanding mandrel 86, having a conical taperingsurface 87 engaging the inner side of the free end of the sleeve, andacting to expand the sleeve outwardly in response torightward movementof mandrel 86 (as viewed in FIG. 3) along axis 68. Between sleeveportion 84 of part 81, and surface 80, the part 81 may externally have atapering conical surface 88 and a short cylindrical surface 89.

For actuation of mandrel 86 axially, this part may be rigidly carried bya reduced diameter stem 90, which extends through and is slidable withina bore 91 formed within block 71, and which has an end portion 92pivotally connected to a cam actuating lever 93 by a pin 94. As will beapparent, the lever 93 has a camming portion 95, which may be bifurcatedto engage a pressure plate 96 at both sides of stem 90, with element 95having camrning surfaces 97 at both of these sides whose radius withrespect to the pivotal axis varies in a manner such that actuation oflever 93 bet-ween the full line position of FIG. 1 and the broken lineposition of that figure acts to pull mandrel 86 to the right, as viewedin-FIG. 3, and to thereby expand sleeve 84 outwardly into tightessentially annular gripping engagement with the inner wall of the rearend portion of barrel 10. For assisting in properly locating sight 28 ofthe gun barrel 10 in a directly upwardly facing position, box 71 maycarry an indicator or indexing element 98 (FIGS. 3 and 4), having apointer end 99 which should directly overlie and'directly align withsight 28 when barrel 10 is turned to a properly oriented position.Element 98 may be mounted for sliding movement parallel to axis 68, bymounting element 98 slidably within a dovetail shaped recess or groove100 in the upper surface of block 71, with the sliding movement of part98 typically being limited by means of a screw 101 whose head engagesthe upper side of part 98 and whose shank extends downwardly through anelongated slot 102 in part 98 and is connected threadedly into block 71.A handle 103 may be formed on part 98, for actuating it To now describethe complete process of ,securing a Against this surface,

6 muzzle attachment to a gun barrel utilizing the apparatus of FIGS. 1through 7, assume that it is desired to mount the choke device 11 ofFIG. 2 on shotgun barrel 10, with the axis 26' along which shot isdirected by choke 11 be ing disposed at a slight angle of one andone-fourth degrees relative to axis 26 of the shotgun barrel. In thiscase, block 41 is pivoted about axis 55 to the position represented inFIG. 3, in which locking pin 65 may be, and is, screwed into threadedopening 61, with the unthreaded end portion 67 of the lock pin beingreceived within the corresponding aperture 63 in flange 38, topositively lock block 41 in the one and one-fourth degree setting. Thissetting is indicated by the fact that the two markings opposite thenumber one and one-fourth coincide, whereas the other markings 69 and 70do not coincide.

Next, the operator may insert muzzle device 11 into passage 42 of block41, with the outer cylindrical surface of the muzzle device beingengaged and centered by the wall of passage 42, and with pivotal axis 25of the muzzle device (-FIG. 2) coinciding with pivotal axis 55 of block41, and axis 26 of the muzzle device (which is also the center aboutwhich the external cylindrical surface of the muzzle device is formed)coinciding with axis 47 of passage 42. Sight 27 on the muzzle device isreceived within slot 127 in the upper portion of block 41, to retain thesight in a proper upwardly directed setting. Screw 44 may then betightened, to securely clamp the muzzle device in a properly centeredand oriented position within block 41, so that the device is veryaccurately located in the desired one and one-half degree angularposition relative to axis 68.

The barrel 10 may be inserted into the muzzle device either prior to orafter attachment of the muzzle device into block 41. Rings 18 and 19 aresecured in the positions of FIG. 2, to attach the muzzle device andbarrel together, and a suitable bonding cement, preferably a very hardsetting epoxy resin, may be applied to the inner surfaces of parts 17,1-8 and 19, and the external surfaces of parts 10 and 19, preferablyfilling the annular clearance spaces 23 and 24, so that as soon as thecement has set, the muzzle device will be rigidly and permanentlyretained in the proper slightly angular position relative to the barrel.

Before the epoxy resin or other cement has had an opportunity to set,the operator slides block 71 forwardly (to the left in FIG. 3) farenough to cause sleeve 84 to extend into the chamber end of barrel 10,as to the FIG. 3 setting, following which the barrel may be turned ifnecessary to properly align sight 28 with index element 98 in a mannerlocating the sight portion of the barrel at exactly the proper upwardlydirected position. The operator locks block 71 in position by means ofscrew 76, and then may swing lever 93 downwardly from the full lineposition of FIG. 1 to the broken line FIG. 1 position, to expand sleeve84 outwardly against the barrel and locate it precisely relative toblock 71. The cement is then hardened while the apparatus holds themuzzle attachment and barrel in the discussed slightly angular relativepositions. If desired, the cement may be an air-drying type of bondingcompound, but preferably it is a thermosetting resin (such as thepreviously mentioned epoxy resin), which is cured by baking the resinfor. an appropriate period, say for example for a period'of two hours at250 Fahrenheit, in the case of an epoxy resin. If necessary, the entiremounting rail 14 and all of the carried parts may be bodily transportedinto a curing oven during the resin curing period. After the resin isset, the barrel and muzzle attachment may be removed from the apparatusand the installation process is complete.

FIG. 8 illustrates a variational form of the invention, which may beconsidered asidentical with that of FIGS. 1 through 7 except as to themanner of construction of the barrel gripping expansible sleeve orcollet 84a, and the coacting parts. In this arrangement, the sleeve hasa first set of circularly spaced slits aextending into the material ofthe sleeve from one of its ends, and has a second set of slits 185aextending into the material of the sleeve from its opposite end, so thatboth ends of the sleeve may be expanded radially against the resilienceof the sleeve material. Mandrel 86a is actuable rightwardly in the samemanner as mandrel 86 of FIG. 3, to expand the 'left end of the sleeve,while the right end of the sleeve is simultaneously engaged by acorrespondingly tapering frustro-conical projection 88a formed on a part81a corresponding to part 81 of FIG. 3. Thus, instead of the right endof the sleeve being rigidly attached to part 81a, in correspondence withthe FIG. 3 arrangement, this right end of the sleeve engages taperedsurface 88a, and is expansible radially by that surface upon rightwardactuation of the mandrel. If desired, the ends of the sleeve may havetapered surfaces shaped in cor-respondence with the engaged taperedsurfaces of parts 86a and 81a, to facilitate the camming action. TheFIG. 8 arrangement acts to locate the right end of the gun barrelsomewhat more effectively than in FIG. 3, by virtue of the fact that thesleeve 84a tends to expand uniformly along its entire length, ratherthan only a one end.

FIG. 9 shows an arrangement in which there is substituted for the part81 of FIG. 3 a rigid element 81b, which may be rigidly retained within ablock 71b (corresponding to block 71 of FIG. 3) by a set screwrepresented at 83b. Part 81b may have a series of externally cylindricalportions 104, 105, 106, 107, 108 and 109, all centered about an axis 68bcorresponding to axis 68 of FIG. 3, and of different diameterscorresponding to the internal diameters of the rear portions of a seriesof different sizes of gun barrels. When using this arrangement, theblock 71b is merely actuated to the left far enough to move theappropriate one of the cylindrical portions 104, 105, 106, 107, 108 or109 into engagement with the inner surface of the rear end portion ofthe gun barrel, to locate the barrel in properly centered position aboutaxis 68b.

In the FIG. 10 arrangement, there is provided a resiliently expanasiblesleeve or collet 840, corresponding to sleeve 84d of FIG. 8, except thatthe sleeve has a series of portions 110, 111, 112, 113 and 114 which areexternally cylindrical and of progressively increasing diameter, allbeing centered about the main axis 68c of the device, for engaging andgripping different sizes of gun barrels (as discussed in connection withFIG. 9). The expanding mandrel 86c engages the reduced diameter end ofcollet 84c, while the opposite end is engageable with a frustroconicalsurface 880 on a part 81c corresponding to parts 81 and 81a of FIGS. 3and 8 respectively. As in FIG. 8, sleeve 840 has two sets oflongitudinal slits 85c and 185s extending into the material of thesleeve from opposite ends thereof, and alternating about the circularextent of the sleeve. The surfaces 115 and 116 which engage cam surfaces880 and 188c may be tapered in correspondence with the engaged camsurfaces. In using the FIG. 10 device, the sleeve 840 is first insertedinto the gun barrel to a position in which the proper one of thesurfaces 110, 111, etc. is received within and substantially engages theinner end portion of the barrel, following which element 860 is actuatedto the right, as viewed in FIG. 10, to expand the sleeve 84c outwardlyinto tight gripping engagement with the barrel. Since slits 85c and 1850extend into the sleeve from its opposite ends, and extend along almostthe entire length of the sleeve, the sleeve expands radially alongsubstantially its entire length upon actuation of mandrel 86a.

FIG. 11 represents another form of the invention, in which there issubstituted for the sleeve 84 of FIG. 3, a disk or ring 84d of rubber orother elastomeric material, which may normally be slightly undersizedwith respect to the particular size of barrel 10d with which the deviceis to be used, but which disk 840. is adapted to be expanded against itsown resilience radially outwardly into tight gripping engagement withthe inner surface of the gun barrel. For effecting such expansion, theright side to part 81 of FIG. 3, and mounted on the face of a block 71dcorresponding to part 71 of FIG. 3. The opposite side of disk or ring84d may be engaged by a member 86d which is carried by a stem W0.adapted to be actuated to the right by a cam lever such as that shown at93 in the first form of the invention. The surface of part 860! whichengages element 84d may be convexly curved, as represented at 186d, tomaximize the extent to which element 84d is expanded outwardly uponright-ward movement of element 86d relative to part 81d. The brokenlines at the periphery of element 84d in FIG. 11 represent the positionto which this part is expanded upon rightward actuation of parts 86d. Aswill be apparent, the part 84d may have a central opening through :whichstern 911d extends, to allow projection of that stem to a position forconnection to an actuating lever.

FIGS. 12 and 13 represent a slightly altered form of muzzle deviceholder 41a, which may be used in connection with different sizes ofadapter rings 141 for adapting the holder to receive muzzle devices ofdifferent gauges. Specifically, each adapter 141 may take the form of asleeve which is received within body 41e and is keyed in position byreception of a pin 142, carried at the forward end of body 412, Withinan axial slit 143 in the sleeve. This slit also enables sleeve 141 toconstrict and expand with body 412. The reduced caliber muzzle device116 is positioned within sleeve 141 behind pin 142, with sight 27aprojecting upwardly through slit 14-3 and into recess 12%. Any number ofadapters of different internal diameters may of course be provided foruse with different muzzle devices, or the holder 41e may be used withoutany adapter for maximum size muzzle devices.

We claim:

1. Apparatus for holding a gun muzzle attachment and a gun barrel havinga muzzle end and a firing chamber end while said attachment is beingsecured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with the muzzle end of a barrel held by said firstfixture but at a predetermined very slight upward angle relative theretoas the barrel and attachment are secured together, to compensate for thepresence of the muzzle attachment in aiming, there being means forindicating precisely when said second fixture and attachment are at saidpredetermined very slight angle to the muzzle end of the barrel.

2. Apparatus for holding a gun muzzle attachment and 'a gun barrelhaving a muzzle end and a firing chamber end while said attachment isbeing secured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun bar-rel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said first fixture including a projection projecting essentially towardsaid second fixture and constructed to extend into and fit closelywithin and thereby position said firing chamber end of the barrel, saidsecond fixture being constructed to hold said attachment in almost exactaxial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence ofthe muzzle attachment in aiming.

3. Apparatus for holding a gun muzzle attachment and a gun barrel havinga muzzle end and a firing chamber end while said attachment is beingsecured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said first fixture including an expansible projection projectingessentially toward said second fixture and constructed to extend intoand expand radially outwardly into tight gripping engagement with andthereby position said firing chamber end of the barrel.

4. Apparatus -for holding a gun muzzle attachment and a gun barrelhaving a muzzle end and a firing chamber end While said attachment isbeing secured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of'the barrel,said second fixture being constnucted to hold said attachment in almostexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barrel'and attachment are secured together, to compensate for the presence ofthe muzzle attachmentin aiming, said first fixture including a sleeveprojecting essentially toward said second fixture and adapted to projectinto and fit closely within and thereby position said firing'chamber endof the barrel, an axially movable mandrel for expanding said sleeve, andmeans tor actuating said mandrel axially.

5. Apparatus for holding a gun muzzle attachment and a gun barrel havinga muzzle end and a firing chamber end while said attachment is beingsecured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gunbar-rel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence or"the muzzle attachment in aiming, said first fixture including a sleeveprojecting essentially toward said second fixture and adapted toproject'into and fit closely within and thereby position said firingchamber end of the barrel, an axially movable mandrel for expanding saidsleeve, a swinging lever having a cam portion operable to shift saidmandrel axially in a sleeve expanding direction upon swinging movementof said lever, and means mounting said lever for swinging movement.

6. Apparatus for holding a gun muzzle attachment and a gun barrel havinga muzzle end and a firing chamber end while said attachment is beingsecured to the barrel,

said apparatus including a support, a first fixture mounted to saidsupport and constructed and positioned to engage and accurately locatesaid firing chamber end of the gun barrel, a second fixture mounted tosaid support for holding and accurately positioning said muzzleattachment at said muzzle end of the barrel, said second fixture beingconstructed to hold said attachment in almost exact axial alignment withthe muzzle end of a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are securedtogether, to compensate for the presence ofthe muzzle attachment in aiming, a mounting structure mounting saidsecond fixture for movement between a plurality of positions for holdingsaid attachment at a plurality of different very slight angles withrespect to the muzzle end of said barrel, and means for indicatingprecisely when said second fixture and attachment are at said differentvery slight angles to the barrel.

7. Apparatus for holding a gun muzzle attachment and a gun barrel havinga muzzle end and a firing chamber end-while said attachment is beingsecured to the barrel, said apparatus including a support, a firstfixture .mounted to said support and constructed and positioned toengage and accurately locate said firing chamber end of the gun barrel,and a second fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with a barrel heldby said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence ofthe muzzle attachment in aiming, there being means for indicatingprecisely when said second fixture and attachment are at saidpredetermined very slight angle to the barrel, said second fixtureincluding a structure containing a recess for receiving said attachmentand opening essentially toward said first fixture and being tightenableradially inwardly against said attachment, and means for releasablytightening said structure against said attachment.

. 8. Apparatus for holding a gun muzzle attachment and a gun barrelhaving a muzzle end and a firing chamber end while said attachment isbeing secured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle at- I tachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence ofthe 'muzzle attachment in aiming, there being means for indiend whilesaid attachment is being secured to the barrel said apparatus includinga support, a first fixture mounted to said support and constructed andpositioned to engage and accurately locate said firing chamber end ofthe gun barrel, and a second fixture mounted to said support for holdingand accurately positioning said muzzle attachment at said muzzle end ofthe barrel, said first fixture including a projection projectingessentially toward said second fixture and constructed to extend intoand fit,

closely within and thereby position said firing chamber end of thebarrel, said second fixture being constructed 7 to hold said attachmentin almost exact axial alignment with a barrel held by said first fixturebut at predetermined very slight upward angle relative thereto as thebarrel and attachment are secured together, to compensate for thepresence of the muzzle attachment in aiming, said projection havingdifferent axially aligned portions of a plurality of different diametersfor selectively engaging and fitting closely within and therebyaccurately locating barrels of different diameters.

10. Apparatus for holding a gun muzzle attachment and a gun barrelhaving a muzzle end and a firing chamber end while said attachment isbeing secured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the present ofthe muzzle attachment in aiming, there being means for indicatingprecisely when said second fixture and attachment are at saidpredetermined very slight angle to the barrel, said first fixture havingan indicator element positioned to indicate when the barrel has beenturned about its axis to a predetermined proper setting with respect tosaid first fixture.

11. Apparatus for holding a gun muzzle attachment and a gun barrelhaving a muzzle end and a firing chamber end while said attachment isbeing secured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, asecond fixture mounted to said support and for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence of Ithe muzzle attachment in aiming, there being means for ber end whilesaid attachment is being secured to the barrel, said apparatus includinga first fixture constructed and positioned to engage and accuratelylocate said firing chamber end of the gun barrel, a second fixture forholding and accurately positioning said muzzle attachment at said muzzleend of the barrel, said first fixture including a projection projectingessentially toward said second fixture and constructed to extend intoand fit closely within and thereby position said firing chamber end ofthe barrel, said second fixture being constructed to hold saidattachment in almost exact axial alignment with a barrel held by saidfirst fixture but at a predetermined very slight upward angle relativethereto as the barrel and attachment are secured together, to compensatefor the presence of the muzzle attachment in aiming, said second fixturecontaining a recess for receiving said attachment and opening towardsaid projection and being tightenable, against said attachment, asupport carrying both of said fixtures, and means mounting one of saidfixtures to said support for a movement relatively toward and away fromthe other.

13. Apparatus for holding a muzzle attachment and a gun barrel having amuzzle end and a firing chamber end While said attachment is beingsecured to the barrel, said apparatus including an elongated support, afirst fixture mounted to said support toward a first end thereof andconstructed and positioned to engage and accurately locate said firingchamber end of the gun barrel, and a second fixture mounted to saidsupport toward a second end thereof for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said first fixture including a projection projecting essentially towardsaid second fixture and constructed to extend into and be expandedtightly against and thereby accurately position said firing chamber endof the barrel, means for expanding said projection against the barrel,said second fixture containing a passage for receiving said attachmentand opening toward said projection and being tightenable radiallyinwardly against the attachment, means for tightening said secondfixture, a pivotal connection mounting said second fixture for slightpivotal movement relative to said support and said first fixture betweena plurality of different positions in which said passage and anattachment therein are disposed in almost exact alignment with saidprojection and a barrel held thereby but at a plurality of differentpredetermined very slight upward angles, in the order of 0 to 2 degrees,relative thereto, and means for securing said second fixture in saiddifferent angular positions.

14. Apparatus for holding a muzzle attachment and a gun barrel having amuzzle end and a firing chamber end while said attachment is beingsecured to the barrel, said apparatus including an elongated support, afirst fixture mounted to said support toward a first end thereof andconstructed and positioned to engage and accurately locate said firingchamber end of the gun barrel, and a second fixture mounted to saidsupport toward a second end thereof for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said first fixture including a projection projecting essentially towardsaid second fixture and constructed to extend into and be expandedtightly against and thereby accurately position said firing chamber endof the barrel, an axially movable mandrel in said projection operable byaxial movement to expand said projection, a swinging lever having a camportion for actuating said mandrel axially, said second fixturecontaining a passage for receiving said attachment and opening towardsaid projection and being tightenable radially inwardly against theattachment, means for tightening said second fixture, a pivotalconnection mounting said second fixture for slight pivotal movementrelative to said support and said first fixture between a plurality ofdifferent positions in which said passage and an attachment therein aredisposed in almost exact alignment with said projection and a barrelheld thereby but at a plurality of different predetermined very slightupward angles, in the order of 0 to 2 degrees relative thereto, meansfor securing said second fixture in said different angular positions,means mounting one of said fixtures for movement along said supporttoward and away from the other fixture and to a plurality of differentpositions, and means for securing said one fixture in any of saiddifferent positions.

15. Apparatus for holding a muzzle attachment and a gun barrel having amuzzle end and a firing chamber end while said attachment is beingsecured to the barrel, said apparatus including an elongated support, amounting part carried by said support, a first fixture mounted to saidmounting part and constructed and positioned to engage and accuratelylocate said firing chamber end of the gun barrel, and a second fixturemounted to said support toward a second end thereof for holding andaccurately positioning said muzzle attachment at said muzzle end of thebarrel, said first fixture including a projection carried by saidmounting part and projecting essentially toward said second fixture andhaving an externally essentially arcuately curved surface constructed toextend into and be expanded tightly against and thereby accuratelyposition said firing chamber end of the barrel, an axially movablemandrel mounted to said mounting part for axial movement relativethereto and operable to expand said projection by said axial movement, alever mounted to said mounting part for swinging movement and connectedto said mandrel to actuate it, a cam carried by said lever and exertingforce against said mounting part toward said second fixture in arelation to actuate the mandrel axially, said second fixture containinga passage for receiving said attachment and opening toward saidprojection and being tightenable radially inwardly against theattachment, means for tightening said second fixture, a pivotalconnection mounting said second fixture for slight pivotal movementrelative to said support and said first fixture between a plurality ofdifferent positions in which said passage and an attachment therein aredisposed in almost exact alignment with said projection and a barrelheld thereby but at a plurality of different predetermined very slightupward angles, in the order of to 2 degrees, relative thereto, means forsecuring said second fixture in said different angular positions, and asliding connection mounting said mounting part for sliding movementtoward and away from said second fixture and including means forsecuring said mounting part in different positions along said support.

16. Apparatus for holding a muzzle attachment of a gun barrel having amuzzle end and a firing chamber end While said attachment is beingsecured to the barrel, and apparatus including an elongated support, amounting part carried by said support, a first fixture mounted to saidmounting part and constructed and positioned to engage and accuratelylocate said firing chamber end of the gun barrel, and a second fixturemounted to said support toward a second end thereof for holding andaccurately positioning said muzzle attachment at said muzzle end of thebarrel, said first fixture including a projection in the form of anaxially split expansible sleeve carried by said mounting part andprojecting essentially toward said second fixture and having anexternally essentially arcuately curved surface constructed to extendinto and be expanded tightly against and thereby accurately positionsaid firing chamber end of the barrel, an axially movable mandrelmounted to said mounting part for axial movement relative thereto andoperable to expand said projection by said axial movement, to a levermounted to said mounting part for swinging movement and connected tosaid mandrel to actuate it, a cam carried by said lever and exertingforce against said mounting part toward said second fixture in arelation to actuate the mandrel axially, said second fixture containinga passage for receiving said attachment and opening toward saidprojection and being tightenable radially inwardly against theattachment, a screw for tightening said second fixture, a carrier partmountedto said support and movably carrying said second fixture, apivotal connection mounting said second fixture to said carrier part forslight pivotal movement relative to said carrier part and said supportand said first fixture between a plurality of different positions inwhich said passage and an attachment therein are disposed in almostexact alignment with said projection and a barrel held thereby but at aplurality of different predetermined very slight upward angles, in theorder of 0 to 2 degrees, relative thereto, said carrier part and saidsecond fixture containing a plurality of sets of apertures adopted toregister in said different pivotal positions of the second fixture,threaded pin means receivable within said registering apertures toreleasably lock said second fixture in said different positions, and asliding connection mounting said mounting part for sliding movementtoward and away from said second fixture and including means forsecuring said mounting part in different positions along said support.

17. Apparatus for holding a gun muzzle attachment and a gun barrelhaving a muzzle end and a firing chamber end While said attachment isbeing secured to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence ofthe muzzle attachment in aiming, said second fixture containing apassage for receiving said attachment and being tightenable radiallyinwardly against the attachment, and said second fixture containing alocalized recess extending radially outwardly thereinto from saidpassage at the upper side thereof and adapted to receive a sight on theattachment to properly locate the sight relative to said barrel.

18. Apparatus for holding a gun muzzle attachment and a gun barrelhaving a muzzle end and a firing chamber end while said attachment isbeing secure to the barrel, said apparatus including a support, a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almostexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence ofthe muzzle attachment in aiming, there being an indicator device on saidfirst fixture for indicating the proper rotary positioning of thebarrel, and means mounting said indicator device for shifting movementrelative to the fixture between active and retracted positions.

19. Apparatus for holding a gun muzzle attachment and a gun barrelhaving a muzzle end and a firing chamber end while said attachment isbeing secured to the barrel, said apparatus including a support a firstfixture mounted to said support and constructed and positioned to engageand accurately locate said firing chamber end of the gun barrel, and asecond fixture mounted to said support for holding and accuratelypositioning said muzzle attachment at said muzzle end of the barrel,said second fixture being constructed to hold said attachment in almsotexact axial alignment with a barrel held by said first fixture but at apredetermined very slight upward angle relative thereto as the barreland attachment are secured together, to compensate for the presence ofthe muzzle attachment in aiming, said second fixture containing apassage for receiving said attachment and being tightenable radiallyinwardly against the attachment, said second fixture containing alocalized recess extending radially outwardly thereinto from saidpassage at the upper side thereof and adapted to receive a sight on theattachment to properly locate the sight relative to said barrel, andthere being a sleeve removably receivable in the said passage to adaptthe second fixture for different size muzzle attachments and containingan opening for passing said sight of an attachment therethrough intosaid localized recess, and interfitting keying means on said secondfixture and said sleeve for retaining the latter in a predeterminedproper rotary orientation.

References Cited by 'the Examiner UNITED STATES PATENTS 402,108 4/1889Ries. 1,368,683 2/1921 Anderson 269- 2,226,078 12/1940 Spahn 113103 X2,227,443 1/ 1941 Denner 269 -5 2 2,497,943 2/ 1950 Ingwer 269692,662,266 12/1953 Powell et al 29--1.1 2,731,712 1/ 1956 Laux 269-82 X2,767,676 10/1956 Johnson et a1. 113103 2,767,677 10/1956 Johnson et a1269--52 X 2,853,771 9/1958 Melville 113102 X 2,853,773 9/1958 Darasko113103 X FOREIGN PATENTS 952,484 11/ 6 Germany.

RQBERT C. RIORDON, Primary Examiner. BROUGHTON G. DURHAM, Examiner.

T. E. BEALL, JR., F. I. POWERS, B. S. MOWRY,

Assistant Examiners.

1. APPARATUS FOR HOLDING A GUN MUZZLE ATTACHMENT AND A GUN BARREL HAVINGA MUZZLE END AND A FIRING CHAMBER END WHILE SAID ATTACHMENT IS BEINGSECURED TO THE BARREL, SAID APPARATUS INCLUDING A SUPPORT, A FIRSTFIXTURE MOUNTED TO SAID SUPPORT AND CONSTRUCTED AND POSITIONED TO ENGAGEAND ACCURATELY LOCATE SAID FIRING CHAMBER END OF THE GUN BARREL, AND ASECOND FIXTURE MOUNTED TO SAID SUPPORT FOR HOLDING AND ACCURATELYPOSITIONING SAID MUZZLE ATTACHMENT AT SAID MUZZLE END OF THE BARREL,SAID SECOND FIXTURE BEING CONSTRUCTED TO HOLD SAID ATTACHMENT IN ALMOSTEXACT AXIAL ALIGNMENT WITH THE MUZZLE END OF A BARREL HELD BY SAID FIRSTFIXTURE BUT AT A PREDETERMINED VERY SLIGHT UPWARD ANGLE RELATIVE THERETOAS THE BARREL AND ATTACHMENT ARE SECURED TOGETHER, TO COMPENSATE FOR THEPRESENCE OF THE MUZZLE ATTACHMENT IN AIMING, THERE BEING MEANS OFINDICATING PRECISELY WHEN SAID SECOD FIXTURE AND ATTACHMENT ARE AT SAIDPREDETERMINED VERY SLIGHT ANGLE TO THE MUZZLE END OF THE BARREL.